That will be a 'vine weevil' - probably Otiorhyncus sulcatus. When found indoors they are frequently emergees from plant pots or have otherwise crawled in beneath doors from the outside. look out for more, if more do manifest themselves then it will more than likely be one of your houseplants at the 'root' of it - pun intended.

No need to worry as they do not nibble on us, pets, furnishings, fabrics or foodstuffs. Larvae feed on plant roots (they love a cyclamen) and adults nibble leaves. Worst case scenario - one or two of your houseplants may look a bit limp ... a small price to pay for a bit of wildlife in the home surely?